blob: 315f13ad382e7963ddc07ed8dc6c79769d8a8141 [file] [log] [blame]
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 * linux/fs/ext4/dir.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/dir.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
Mingming Cao617ba132006-10-11 01:20:53 -070015 * ext4 directory handling functions
Dave Kleikampac27a0e2006-10-11 01:20:50 -070016 *
17 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 *
20 * Hash Tree Directory indexing (c) 2001 Daniel Phillips
21 *
22 */
23
24#include <linux/fs.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070025#include <linux/buffer_head.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070026#include <linux/slab.h>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040027#include "ext4.h"
Tao Ma65d165d2012-12-10 14:05:59 -050028#include "xattr.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070029
Al Viro725bebb2013-05-17 16:08:53 -040030static int ext4_dx_readdir(struct file *, struct dir_context *);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070031
Fan Yongd1f52732012-03-18 22:44:40 -040032/**
33 * Check if the given dir-inode refers to an htree-indexed directory
Anatol Pomozov70261f52013-08-28 14:40:12 -040034 * (or a directory which could potentially get converted to use htree
Fan Yongd1f52732012-03-18 22:44:40 -040035 * indexing).
36 *
37 * Return 1 if it is a dx dir, 0 if not
38 */
39static int is_dx_dir(struct inode *inode)
40{
41 struct super_block *sb = inode->i_sb;
42
43 if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
44 EXT4_FEATURE_COMPAT_DIR_INDEX) &&
45 ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
Tao Ma8af0f082013-04-19 17:53:09 -040046 ((inode->i_size >> sb->s_blocksize_bits) == 1) ||
47 ext4_has_inline_data(inode)))
Fan Yongd1f52732012-03-18 22:44:40 -040048 return 1;
49
50 return 0;
51}
52
Theodore Ts'ocad3f002010-12-19 22:07:02 -050053/*
54 * Return 0 if the directory entry is OK, and 1 if there is a problem
55 *
56 * Note: this is the opposite of what ext2 and ext3 historically returned...
Tao Ma65d165d2012-12-10 14:05:59 -050057 *
58 * bh passed here can be an inode block or a dir data block, depending
59 * on the inode inline data flag.
Theodore Ts'ocad3f002010-12-19 22:07:02 -050060 */
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040061int __ext4_check_dir_entry(const char *function, unsigned int line,
Theodore Ts'of7c21172011-01-10 12:10:55 -050062 struct inode *dir, struct file *filp,
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040063 struct ext4_dir_entry_2 *de,
Tao Ma226ba972012-12-10 14:05:58 -050064 struct buffer_head *bh, char *buf, int size,
Theodore Ts'o60fd4da2010-07-27 11:54:40 -040065 unsigned int offset)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070066{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040067 const char *error_msg = NULL;
Wei Yongjun3d0518f2009-02-14 23:01:36 -050068 const int rlen = ext4_rec_len_from_disk(de->rec_len,
69 dir->i_sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070070
Theodore Ts'ocad3f002010-12-19 22:07:02 -050071 if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070072 error_msg = "rec_len is smaller than minimal";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050073 else if (unlikely(rlen % 4 != 0))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070074 error_msg = "rec_len % 4 != 0";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050075 else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070076 error_msg = "rec_len is too small for name_len";
Tao Ma226ba972012-12-10 14:05:58 -050077 else if (unlikely(((char *) de - buf) + rlen > size))
78 error_msg = "directory entry across range";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050079 else if (unlikely(le32_to_cpu(de->inode) >
80 le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070081 error_msg = "inode out of bounds";
Theodore Ts'ocad3f002010-12-19 22:07:02 -050082 else
83 return 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070084
Theodore Ts'of7c21172011-01-10 12:10:55 -050085 if (filp)
Dan Carpenter4fda4002012-02-20 17:53:05 -050086 ext4_error_file(filp, function, line, bh->b_blocknr,
Theodore Ts'of7c21172011-01-10 12:10:55 -050087 "bad entry in directory: %s - offset=%u(%u), "
88 "inode=%u, rec_len=%d, name_len=%d",
Tao Ma226ba972012-12-10 14:05:58 -050089 error_msg, (unsigned) (offset % size),
Theodore Ts'of7c21172011-01-10 12:10:55 -050090 offset, le32_to_cpu(de->inode),
91 rlen, de->name_len);
92 else
Dan Carpenter4fda4002012-02-20 17:53:05 -050093 ext4_error_inode(dir, function, line, bh->b_blocknr,
Theodore Ts'of7c21172011-01-10 12:10:55 -050094 "bad entry in directory: %s - offset=%u(%u), "
95 "inode=%u, rec_len=%d, name_len=%d",
Tao Ma226ba972012-12-10 14:05:58 -050096 error_msg, (unsigned) (offset % size),
Theodore Ts'of7c21172011-01-10 12:10:55 -050097 offset, le32_to_cpu(de->inode),
98 rlen, de->name_len);
99
Theodore Ts'ocad3f002010-12-19 22:07:02 -0500100 return 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700101}
102
Al Viro725bebb2013-05-17 16:08:53 -0400103static int ext4_readdir(struct file *file, struct dir_context *ctx)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700104{
Theodore Ts'o498e5f22008-11-05 00:14:04 -0500105 unsigned int offset;
Giedrius Rekasiusaa13d5f2014-05-27 12:48:55 -0400106 int i;
Mingming Cao617ba132006-10-11 01:20:53 -0700107 struct ext4_dir_entry_2 *de;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700108 int err;
Al Viro725bebb2013-05-17 16:08:53 -0400109 struct inode *inode = file_inode(file);
Fan Yongd1f52732012-03-18 22:44:40 -0400110 struct super_block *sb = inode->i_sb;
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400111 int dir_has_error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700112
Fan Yongd1f52732012-03-18 22:44:40 -0400113 if (is_dx_dir(inode)) {
Al Viro725bebb2013-05-17 16:08:53 -0400114 err = ext4_dx_readdir(file, ctx);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700115 if (err != ERR_BAD_DX_DIR) {
Al Viro725bebb2013-05-17 16:08:53 -0400116 return err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700117 }
118 /*
119 * We don't set the inode dirty flag since it's not
120 * critical that it get flushed back to the disk.
121 */
Al Viro725bebb2013-05-17 16:08:53 -0400122 ext4_clear_inode_flag(file_inode(file),
Theodore Ts'o07a03822010-06-14 09:54:48 -0400123 EXT4_INODE_INDEX);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700124 }
Tao Ma8af0f082013-04-19 17:53:09 -0400125
126 if (ext4_has_inline_data(inode)) {
127 int has_inline_data = 1;
Al Viro725bebb2013-05-17 16:08:53 -0400128 int ret = ext4_read_inline_dir(file, ctx,
Tao Ma8af0f082013-04-19 17:53:09 -0400129 &has_inline_data);
130 if (has_inline_data)
131 return ret;
132 }
133
Al Viro725bebb2013-05-17 16:08:53 -0400134 offset = ctx->pos & (sb->s_blocksize - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700135
Al Viro725bebb2013-05-17 16:08:53 -0400136 while (ctx->pos < inode->i_size) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400137 struct ext4_map_blocks map;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700138 struct buffer_head *bh = NULL;
139
Al Viro725bebb2013-05-17 16:08:53 -0400140 map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb);
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400141 map.m_len = 1;
142 err = ext4_map_blocks(NULL, inode, &map, 0);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700143 if (err > 0) {
Theodore Ts'o2ed88682010-05-16 20:00:00 -0400144 pgoff_t index = map.m_pblk >>
Fengguang Wudc7868f2007-07-19 01:48:04 -0700145 (PAGE_CACHE_SHIFT - inode->i_blkbits);
Al Viro725bebb2013-05-17 16:08:53 -0400146 if (!ra_has_index(&file->f_ra, index))
Rusty Russellcf914a72007-07-19 01:48:08 -0700147 page_cache_sync_readahead(
Fengguang Wudc7868f2007-07-19 01:48:04 -0700148 sb->s_bdev->bd_inode->i_mapping,
Al Viro725bebb2013-05-17 16:08:53 -0400149 &file->f_ra, file,
Rusty Russellcf914a72007-07-19 01:48:08 -0700150 index, 1);
Al Viro725bebb2013-05-17 16:08:53 -0400151 file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
Theodore Ts'o1c215022014-08-29 20:52:15 -0400152 bh = ext4_bread(NULL, inode, map.m_lblk, 0);
153 if (IS_ERR(bh))
154 return PTR_ERR(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700155 }
156
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700157 if (!bh) {
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400158 if (!dir_has_error) {
Al Viro725bebb2013-05-17 16:08:53 -0400159 EXT4_ERROR_FILE(file, 0,
Theodore Ts'of7c21172011-01-10 12:10:55 -0500160 "directory contains a "
161 "hole at offset %llu",
Al Viro725bebb2013-05-17 16:08:53 -0400162 (unsigned long long) ctx->pos);
Eric Sandeen9d9f1772008-10-09 11:15:52 -0400163 dir_has_error = 1;
164 }
Eric Sandeene6c40212006-12-06 20:36:28 -0800165 /* corrupt size? Maybe no more blocks to read */
Al Viro725bebb2013-05-17 16:08:53 -0400166 if (ctx->pos > inode->i_blocks << 9)
Eric Sandeene6c40212006-12-06 20:36:28 -0800167 break;
Al Viro725bebb2013-05-17 16:08:53 -0400168 ctx->pos += sb->s_blocksize - offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700169 continue;
170 }
171
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400172 /* Check the checksum */
173 if (!buffer_verified(bh) &&
174 !ext4_dirent_csum_verify(inode,
175 (struct ext4_dir_entry *)bh->b_data)) {
Al Viro725bebb2013-05-17 16:08:53 -0400176 EXT4_ERROR_FILE(file, 0, "directory fails checksum "
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400177 "at offset %llu",
Al Viro725bebb2013-05-17 16:08:53 -0400178 (unsigned long long)ctx->pos);
179 ctx->pos += sb->s_blocksize - offset;
Guo Chaod5ac7772013-01-28 21:23:24 -0500180 brelse(bh);
Darrick J. Wongb0336e82012-04-29 18:41:10 -0400181 continue;
182 }
183 set_buffer_verified(bh);
184
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700185 /* If the dir block has changed since the last call to
186 * readdir(2), then we might be pointing to an invalid
187 * dirent right now. Scan from the start of the block
188 * to make sure. */
Al Viro725bebb2013-05-17 16:08:53 -0400189 if (file->f_version != inode->i_version) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700190 for (i = 0; i < sb->s_blocksize && i < offset; ) {
Mingming Cao617ba132006-10-11 01:20:53 -0700191 de = (struct ext4_dir_entry_2 *)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700192 (bh->b_data + i);
193 /* It's too expensive to do a full
194 * dirent test each time round this
195 * loop, but we do have to test at
196 * least that it is non-zero. A
197 * failure will be detected in the
198 * dirent test below. */
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500199 if (ext4_rec_len_from_disk(de->rec_len,
200 sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700201 break;
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500202 i += ext4_rec_len_from_disk(de->rec_len,
203 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700204 }
205 offset = i;
Al Viro725bebb2013-05-17 16:08:53 -0400206 ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700207 | offset;
Al Viro725bebb2013-05-17 16:08:53 -0400208 file->f_version = inode->i_version;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700209 }
210
Al Viro725bebb2013-05-17 16:08:53 -0400211 while (ctx->pos < inode->i_size
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700212 && offset < sb->s_blocksize) {
Mingming Cao617ba132006-10-11 01:20:53 -0700213 de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
Al Viro725bebb2013-05-17 16:08:53 -0400214 if (ext4_check_dir_entry(inode, file, de, bh,
Tao Ma226ba972012-12-10 14:05:58 -0500215 bh->b_data, bh->b_size,
216 offset)) {
Andrew Morton63f57932006-10-11 01:21:24 -0700217 /*
Al Viro725bebb2013-05-17 16:08:53 -0400218 * On error, skip to the next block
Andrew Morton63f57932006-10-11 01:21:24 -0700219 */
Al Viro725bebb2013-05-17 16:08:53 -0400220 ctx->pos = (ctx->pos |
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700221 (sb->s_blocksize - 1)) + 1;
Al Viro725bebb2013-05-17 16:08:53 -0400222 break;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700223 }
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500224 offset += ext4_rec_len_from_disk(de->rec_len,
225 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700226 if (le32_to_cpu(de->inode)) {
Al Viro725bebb2013-05-17 16:08:53 -0400227 if (!dir_emit(ctx, de->name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700228 de->name_len,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700229 le32_to_cpu(de->inode),
Al Viro725bebb2013-05-17 16:08:53 -0400230 get_dtype(sb, de->file_type))) {
231 brelse(bh);
232 return 0;
233 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700234 }
Al Viro725bebb2013-05-17 16:08:53 -0400235 ctx->pos += ext4_rec_len_from_disk(de->rec_len,
Wei Yongjun3d0518f2009-02-14 23:01:36 -0500236 sb->s_blocksize);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700237 }
238 offset = 0;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400239 brelse(bh);
Al Viro725bebb2013-05-17 16:08:53 -0400240 if (ctx->pos < inode->i_size) {
241 if (!dir_relax(inode))
242 return 0;
243 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700244 }
Al Viro725bebb2013-05-17 16:08:53 -0400245 return 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700246}
247
Fan Yongd1f52732012-03-18 22:44:40 -0400248static inline int is_32bit_api(void)
249{
250#ifdef CONFIG_COMPAT
251 return is_compat_task();
252#else
253 return (BITS_PER_LONG == 32);
254#endif
255}
256
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700257/*
258 * These functions convert from the major/minor hash to an f_pos
Fan Yongd1f52732012-03-18 22:44:40 -0400259 * value for dx directories
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700260 *
Fan Yongd1f52732012-03-18 22:44:40 -0400261 * Upper layer (for example NFS) should specify FMODE_32BITHASH or
262 * FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
263 * directly on both 32-bit and 64-bit nodes, under such case, neither
264 * FMODE_32BITHASH nor FMODE_64BITHASH is specified.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700265 */
Fan Yongd1f52732012-03-18 22:44:40 -0400266static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
267{
268 if ((filp->f_mode & FMODE_32BITHASH) ||
269 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
270 return major >> 1;
271 else
272 return ((__u64)(major >> 1) << 32) | (__u64)minor;
273}
274
275static inline __u32 pos2maj_hash(struct file *filp, loff_t pos)
276{
277 if ((filp->f_mode & FMODE_32BITHASH) ||
278 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
279 return (pos << 1) & 0xffffffff;
280 else
281 return ((pos >> 32) << 1) & 0xffffffff;
282}
283
284static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
285{
286 if ((filp->f_mode & FMODE_32BITHASH) ||
287 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
288 return 0;
289 else
290 return pos & 0xffffffff;
291}
292
293/*
294 * Return 32- or 64-bit end-of-file for dx directories
295 */
296static inline loff_t ext4_get_htree_eof(struct file *filp)
297{
298 if ((filp->f_mode & FMODE_32BITHASH) ||
299 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
300 return EXT4_HTREE_EOF_32BIT;
301 else
302 return EXT4_HTREE_EOF_64BIT;
303}
304
305
306/*
Eric Sandeenec7268c2012-04-30 13:14:03 -0500307 * ext4_dir_llseek() calls generic_file_llseek_size to handle htree
308 * directories, where the "offset" is in terms of the filename hash
309 * value instead of the byte offset.
Fan Yongd1f52732012-03-18 22:44:40 -0400310 *
Eric Sandeenec7268c2012-04-30 13:14:03 -0500311 * Because we may return a 64-bit hash that is well beyond offset limits,
312 * we need to pass the max hash as the maximum allowable offset in
313 * the htree directory case.
314 *
315 * For non-htree, ext4_llseek already chooses the proper max offset.
Fan Yongd1f52732012-03-18 22:44:40 -0400316 */
Zheng Liud4e43952013-03-02 17:24:05 -0500317static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence)
Fan Yongd1f52732012-03-18 22:44:40 -0400318{
319 struct inode *inode = file->f_mapping->host;
Fan Yongd1f52732012-03-18 22:44:40 -0400320 int dx_dir = is_dx_dir(inode);
Eric Sandeenec7268c2012-04-30 13:14:03 -0500321 loff_t htree_max = ext4_get_htree_eof(file);
Fan Yongd1f52732012-03-18 22:44:40 -0400322
Eric Sandeenec7268c2012-04-30 13:14:03 -0500323 if (likely(dx_dir))
Andrew Morton965c8e52012-12-17 15:59:39 -0800324 return generic_file_llseek_size(file, offset, whence,
Eric Sandeenec7268c2012-04-30 13:14:03 -0500325 htree_max, htree_max);
326 else
Andrew Morton965c8e52012-12-17 15:59:39 -0800327 return ext4_llseek(file, offset, whence);
Fan Yongd1f52732012-03-18 22:44:40 -0400328}
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700329
330/*
331 * This structure holds the nodes of the red-black tree used to store
332 * the directory entry in hash order.
333 */
334struct fname {
335 __u32 hash;
336 __u32 minor_hash;
337 struct rb_node rb_hash;
338 struct fname *next;
339 __u32 inode;
340 __u8 name_len;
341 __u8 file_type;
342 char name[0];
343};
344
345/*
346 * This functoin implements a non-recursive way of freeing all of the
347 * nodes in the red-black tree.
348 */
349static void free_rb_tree_fname(struct rb_root *root)
350{
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800351 struct fname *fname, *next;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700352
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800353 rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700354 while (fname) {
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400355 struct fname *old = fname;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700356 fname = fname->next;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400357 kfree(old);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700358 }
Cody P Schaferd1866bd2014-01-23 15:56:10 -0800359
360 *root = RB_ROOT;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700361}
362
363
Fan Yongd1f52732012-03-18 22:44:40 -0400364static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
365 loff_t pos)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700366{
367 struct dir_private_info *p;
368
Shen Feng69baee02008-07-11 19:27:31 -0400369 p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700370 if (!p)
371 return NULL;
Fan Yongd1f52732012-03-18 22:44:40 -0400372 p->curr_hash = pos2maj_hash(filp, pos);
373 p->curr_minor_hash = pos2min_hash(filp, pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700374 return p;
375}
376
Mingming Cao617ba132006-10-11 01:20:53 -0700377void ext4_htree_free_dir_info(struct dir_private_info *p)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700378{
379 free_rb_tree_fname(&p->root);
380 kfree(p);
381}
382
383/*
384 * Given a directory entry, enter it into the fname rb tree.
Theodore Ts'o2f618302015-04-12 00:56:26 -0400385 *
386 * When filename encryption is enabled, the dirent will hold the
387 * encrypted filename, while the htree will hold decrypted filename.
388 * The decrypted filename is passed in via ent_name. parameter.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700389 */
Mingming Cao617ba132006-10-11 01:20:53 -0700390int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700391 __u32 minor_hash,
Theodore Ts'o2f618302015-04-12 00:56:26 -0400392 struct ext4_dir_entry_2 *dirent,
393 struct ext4_str *ent_name)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700394{
395 struct rb_node **p, *parent = NULL;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400396 struct fname *fname, *new_fn;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700397 struct dir_private_info *info;
398 int len;
399
Joe Perchesa271fe82010-07-27 11:56:04 -0400400 info = dir_file->private_data;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700401 p = &info->root.rb_node;
402
403 /* Create and allocate the fname structure */
Theodore Ts'o2f618302015-04-12 00:56:26 -0400404 len = sizeof(struct fname) + ent_name->len + 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700405 new_fn = kzalloc(len, GFP_KERNEL);
406 if (!new_fn)
407 return -ENOMEM;
408 new_fn->hash = hash;
409 new_fn->minor_hash = minor_hash;
410 new_fn->inode = le32_to_cpu(dirent->inode);
Theodore Ts'o2f618302015-04-12 00:56:26 -0400411 new_fn->name_len = ent_name->len;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700412 new_fn->file_type = dirent->file_type;
Theodore Ts'o2f618302015-04-12 00:56:26 -0400413 memcpy(new_fn->name, ent_name->name, ent_name->len);
414 new_fn->name[ent_name->len] = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700415
416 while (*p) {
417 parent = *p;
418 fname = rb_entry(parent, struct fname, rb_hash);
419
420 /*
421 * If the hash and minor hash match up, then we put
422 * them on a linked list. This rarely happens...
423 */
424 if ((new_fn->hash == fname->hash) &&
425 (new_fn->minor_hash == fname->minor_hash)) {
426 new_fn->next = fname->next;
427 fname->next = new_fn;
428 return 0;
429 }
430
431 if (new_fn->hash < fname->hash)
432 p = &(*p)->rb_left;
433 else if (new_fn->hash > fname->hash)
434 p = &(*p)->rb_right;
435 else if (new_fn->minor_hash < fname->minor_hash)
436 p = &(*p)->rb_left;
437 else /* if (new_fn->minor_hash > fname->minor_hash) */
438 p = &(*p)->rb_right;
439 }
440
441 rb_link_node(&new_fn->rb_hash, parent, p);
442 rb_insert_color(&new_fn->rb_hash, &info->root);
443 return 0;
444}
445
446
447
448/*
Mingming Cao617ba132006-10-11 01:20:53 -0700449 * This is a helper function for ext4_dx_readdir. It calls filldir
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700450 * for all entres on the fname linked list. (Normally there is only
451 * one entry on the linked list, unless there are 62 bit hash collisions.)
452 */
Al Viro725bebb2013-05-17 16:08:53 -0400453static int call_filldir(struct file *file, struct dir_context *ctx,
454 struct fname *fname)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700455{
Al Viro725bebb2013-05-17 16:08:53 -0400456 struct dir_private_info *info = file->private_data;
457 struct inode *inode = file_inode(file);
458 struct super_block *sb = inode->i_sb;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700459
460 if (!fname) {
Theodore Ts'o92b97812012-03-19 23:41:49 -0400461 ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: "
462 "called with null fname?!?", __func__, __LINE__,
463 inode->i_ino, current->comm);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700464 return 0;
465 }
Al Viro725bebb2013-05-17 16:08:53 -0400466 ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700467 while (fname) {
Al Viro725bebb2013-05-17 16:08:53 -0400468 if (!dir_emit(ctx, fname->name,
469 fname->name_len,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700470 fname->inode,
Al Viro725bebb2013-05-17 16:08:53 -0400471 get_dtype(sb, fname->file_type))) {
Theodore Ts'od0156412008-08-19 21:57:43 -0400472 info->extra_fname = fname;
Al Viro725bebb2013-05-17 16:08:53 -0400473 return 1;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700474 }
475 fname = fname->next;
476 }
477 return 0;
478}
479
Al Viro725bebb2013-05-17 16:08:53 -0400480static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700481{
Al Viro725bebb2013-05-17 16:08:53 -0400482 struct dir_private_info *info = file->private_data;
483 struct inode *inode = file_inode(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700484 struct fname *fname;
485 int ret;
486
487 if (!info) {
Al Viro725bebb2013-05-17 16:08:53 -0400488 info = ext4_htree_create_dir_info(file, ctx->pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700489 if (!info)
490 return -ENOMEM;
Al Viro725bebb2013-05-17 16:08:53 -0400491 file->private_data = info;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700492 }
493
Al Viro725bebb2013-05-17 16:08:53 -0400494 if (ctx->pos == ext4_get_htree_eof(file))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700495 return 0; /* EOF */
496
497 /* Some one has messed with f_pos; reset the world */
Al Viro725bebb2013-05-17 16:08:53 -0400498 if (info->last_pos != ctx->pos) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700499 free_rb_tree_fname(&info->root);
500 info->curr_node = NULL;
501 info->extra_fname = NULL;
Al Viro725bebb2013-05-17 16:08:53 -0400502 info->curr_hash = pos2maj_hash(file, ctx->pos);
503 info->curr_minor_hash = pos2min_hash(file, ctx->pos);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700504 }
505
506 /*
507 * If there are any leftover names on the hash collision
508 * chain, return them first.
509 */
Theodore Ts'od0156412008-08-19 21:57:43 -0400510 if (info->extra_fname) {
Al Viro725bebb2013-05-17 16:08:53 -0400511 if (call_filldir(file, ctx, info->extra_fname))
Theodore Ts'od0156412008-08-19 21:57:43 -0400512 goto finished;
Theodore Ts'od0156412008-08-19 21:57:43 -0400513 info->extra_fname = NULL;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400514 goto next_node;
Theodore Ts'od0156412008-08-19 21:57:43 -0400515 } else if (!info->curr_node)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700516 info->curr_node = rb_first(&info->root);
517
518 while (1) {
519 /*
520 * Fill the rbtree if we have no more entries,
521 * or the inode has changed since we last read in the
522 * cached entries.
523 */
524 if ((!info->curr_node) ||
Al Viro725bebb2013-05-17 16:08:53 -0400525 (file->f_version != inode->i_version)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700526 info->curr_node = NULL;
527 free_rb_tree_fname(&info->root);
Al Viro725bebb2013-05-17 16:08:53 -0400528 file->f_version = inode->i_version;
529 ret = ext4_htree_fill_tree(file, info->curr_hash,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700530 info->curr_minor_hash,
531 &info->next_hash);
532 if (ret < 0)
533 return ret;
534 if (ret == 0) {
Al Viro725bebb2013-05-17 16:08:53 -0400535 ctx->pos = ext4_get_htree_eof(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700536 break;
537 }
538 info->curr_node = rb_first(&info->root);
539 }
540
541 fname = rb_entry(info->curr_node, struct fname, rb_hash);
542 info->curr_hash = fname->hash;
543 info->curr_minor_hash = fname->minor_hash;
Al Viro725bebb2013-05-17 16:08:53 -0400544 if (call_filldir(file, ctx, fname))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700545 break;
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400546 next_node:
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700547 info->curr_node = rb_next(info->curr_node);
Theodore Ts'o3c37fc82008-10-25 11:39:08 -0400548 if (info->curr_node) {
549 fname = rb_entry(info->curr_node, struct fname,
550 rb_hash);
551 info->curr_hash = fname->hash;
552 info->curr_minor_hash = fname->minor_hash;
553 } else {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700554 if (info->next_hash == ~0) {
Al Viro725bebb2013-05-17 16:08:53 -0400555 ctx->pos = ext4_get_htree_eof(file);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700556 break;
557 }
558 info->curr_hash = info->next_hash;
559 info->curr_minor_hash = 0;
560 }
561 }
562finished:
Al Viro725bebb2013-05-17 16:08:53 -0400563 info->last_pos = ctx->pos;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700564 return 0;
565}
566
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400567static int ext4_release_dir(struct inode *inode, struct file *filp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700568{
Andrew Morton63f57932006-10-11 01:21:24 -0700569 if (filp->private_data)
Mingming Cao617ba132006-10-11 01:20:53 -0700570 ext4_htree_free_dir_info(filp->private_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700571
572 return 0;
573}
Fan Yongd1f52732012-03-18 22:44:40 -0400574
Darrick J. Wong40b163f2014-07-28 13:06:26 -0400575int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,
576 int buf_size)
577{
578 struct ext4_dir_entry_2 *de;
579 int nlen, rlen;
580 unsigned int offset = 0;
581 char *top;
582
583 de = (struct ext4_dir_entry_2 *)buf;
584 top = buf + buf_size;
585 while ((char *) de < top) {
586 if (ext4_check_dir_entry(dir, NULL, de, bh,
587 buf, buf_size, offset))
588 return -EIO;
589 nlen = EXT4_DIR_REC_LEN(de->name_len);
590 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
591 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
592 offset += rlen;
593 }
594 if ((char *) de > top)
595 return -EIO;
596
597 return 0;
598}
599
Fan Yongd1f52732012-03-18 22:44:40 -0400600const struct file_operations ext4_dir_operations = {
601 .llseek = ext4_dir_llseek,
602 .read = generic_read_dir,
Al Viro725bebb2013-05-17 16:08:53 -0400603 .iterate = ext4_readdir,
Fan Yongd1f52732012-03-18 22:44:40 -0400604 .unlocked_ioctl = ext4_ioctl,
605#ifdef CONFIG_COMPAT
606 .compat_ioctl = ext4_compat_ioctl,
607#endif
608 .fsync = ext4_sync_file,
609 .release = ext4_release_dir,
610};